U.S. patent application number 17/502471 was filed with the patent office on 2022-04-21 for rotary cutting tool and cutting tool parts.
The applicant listed for this patent is KENNAMETAL INC.. Invention is credited to Marcelo Euripedes da Silva, Christoph Gey, Patrick Kuhlemann.
Application Number | 20220118526 17/502471 |
Document ID | / |
Family ID | 1000005957538 |
Filed Date | 2022-04-21 |
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United States Patent
Application |
20220118526 |
Kind Code |
A1 |
Gey; Christoph ; et
al. |
April 21, 2022 |
Rotary cutting tool and cutting tool parts
Abstract
The invention describes a rotary cutting tool, in particular a
drill, which comprises a first cutting tool part having at least
one cutting edge and a second cutting tool part which comprises a
cutting tool shank. The first cutting tool part and the second
cutting tool part are releasably connected to one another via a
coupling mechanism which comprises a coupling cam that is mounted
on one of the two cutting tool parts such that it can rotate about
an axis of rotation and, in a coupling position, abuts an
engagement surface on the other cutting tool part. The invention
also presents a cutting tool part, in particular a cutting tool
base, and a further cutting tool part, in particular a cutting
tip.
Inventors: |
Gey; Christoph; (Stetten,
CH) ; Kuhlemann; Patrick; (Fuerth, DE) ;
Euripedes da Silva; Marcelo; (Piracicaba, BR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KENNAMETAL INC. |
Latrobe |
PA |
US |
|
|
Family ID: |
1000005957538 |
Appl. No.: |
17/502471 |
Filed: |
October 15, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B23B 27/16 20130101 |
International
Class: |
B23B 27/16 20060101
B23B027/16 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 15, 2020 |
DE |
102020127229.4 |
Claims
1. A rotary cutting tool comprising: a first cutting tool part on
which at least one cutting edge is disposed and a second cutting
tool part which comprises a cutting tool shank, wherein the first
cutting tool part and the second cutting tool part are adjacent to
one another along an axis of rotation of the rotary cutting tool
and are releasably connected to one another via a coupling
mechanism, wherein the coupling mechanism comprises a coupling cam
that is mounted on one of the two cutting tool parts such that it
can rotate about an axis of rotation and, in a coupling position,
abuts an engagement surface on the other cutting tool part, so that
the first cutting tool part and the second cutting tool part are
coupled in the direction of the axis of rotation.
2. The rotary cutting tool according to claim 1, wherein, in the
coupling position of the coupling cam, the first cutting tool part
and the second cutting tool part are coupled in a form-locking
manner in the direction of the axis of rotation.
3. The rotary cutting tool according to claim 1, wherein the axis
of rotation of the coupling cam extends transverse to the axis of
rotation of the rotary cutting tool.
4. The rotary cutting tool according to claim 1, wherein the
coupling cam is substantially elliptical or parabolic in a
cross-section oriented substantially perpendicular to the axis of
rotation.
5. The rotary cutting tool according to claim 1, wherein the
coupling cam is disposed in an end portion of the first cutting
tool part or the second cutting tool part facing the respective
other cutting tool part.
6. The rotary cutting tool according to claim 1, wherein the
coupling cam is seated on a camshaft that is mounted within the
first cutting tool part or the second cutting tool part such that
it can rotate about the axis of rotation.
7. The rotary cutting tool according to claim 6, wherein the
coupling cam is produced in one piece with the camshaft or is
integrally connected to the camshaft.
8. The rotary cutting tool according to claim 1, wherein the
engagement surface forms an undercut which acts in the direction of
the axis of rotation of the rotary cutting tool and in a separating
direction of the cutting tool parts.
9. The rotary cutting tool according to claim 1, wherein the
engagement surface comprises a cylinder jacket surface portion.
10. The rotary cutting tool according to claim 9, wherein a central
axis associated with the cylinder jacket surface portion extends
transverse to the axis of rotation of the rotary cutting tool.
11. The rotary cutting tool of claim 1, wherein the engagement
surface is configured as a section of a coupling groove, wherein
the coupling groove is provided on the first cutting tool part or
on the second cutting tool part and an opening of the coupling
groove faces in the direction of the respective other cutting tool
part.
12. The rotary cutting tool according to claim 11, wherein the
engagement surface is disposed in the region of a groove base of
the coupling groove.
13. The rotary cutting tool according to claim 11, wherein the
coupling cam and the coupling groove are matched to one another
such that, in an assembly position, the coupling cam can be slid
along the axis of rotation of the rotary cutting tool inside the
coupling groove.
14. A cutting tool part for a rotary cutting tool according to
claim 1 comprising a coupling interface for coupling the cutting
tool part to another cutting tool part, wherein the coupling
interface comprises a rotatably mounted coupling cam.
15. A cutting tool part for a rotary cutting tool according to
claim 1 comprising a coupling interface for coupling the cutting
tool part to another cutting tool part, wherein the coupling
interface comprises an engagement surface for a coupling cam.
16. The rotary cutting tool according to claim 1, wherein the
rotary cutting tool is a drill.
17. The rotary cutting tool according to claim 3, wherein the axis
of rotation of the coupling cam extends normal to the axis of
rotation of the rotary cutting tool.
18. The rotary cutting tool according to claim 6, wherein a tool
engagement contour is provided on at least one end of the
camshaft.
19. The rotary cutting tool according to claim 9, wherein the
cylinder jacket portion is a circular cylinder jacket surface
portion or a jacket surface portion of a cylinder having an
elliptical bottom surface.
20. The rotary cutting tool of claim 10, wherein the central axis
extends substantially parallel to the axis of rotation of the
coupling cam.
Description
RELATED APPLICATION DATA
[0001] The present invention claims priority pursuant to 35 U.S.C.
.sctn. 119(a) to German Patent Application Number 102020127229.4
filed Oct. 15, 2020 which is incorporated herein by reference in
its entirety.
FIELD
[0002] The invention relates to a rotary cutting tool, in
particular a drill, comprising a first cutting tool part on which
at least one cutting edge is disposed and a second cutting tool
part which comprises a cutting tool shank. The first cutting tool
part and the second cutting tool part are adjacent to one another
along an axis of rotation of the rotary cutting tool and are
releasably connected to one another via a coupling mechanism.
[0003] The invention is also directed to a cutting tool part, in
particular a cutting tool base, for such a rotary cutting tool
which comprises a coupling interface for coupling the cutting tool
part to another cutting tool part. Such a cutting tool part is
sometimes also referred to as a cutting tool shank, which, in view
of the fact that it does not only include the cutting tool shank,
is overly simplified.
[0004] The invention is also directed to a further cutting tool
part, in particular a cutting tip, for such a rotary cutting tool
which comprises a coupling interface for coupling the cutting tool
part to another cutting tool part.
BACKGROUND
[0005] Such rotary cutting tools and cutting tool parts provided
for them are known from the state of the art.
[0006] Due to the fact that the cutting tool part on which the at
least one cutting edge is disposed can be removed from the cutting
tool part that comprises the cutting tool shank, such rotary
cutting tools are also referred to as rotary cutting tools having
exchangeable cutting tips or, more generally, as modular rotary
cutting tools.
[0007] Overall, the objective is to provide a rotary cutting tool
in which the cutting tool parts that are subject to wear during
operation can easily be replaced so that the rotary cutting tool
can be used for a long period of time. A side effect of this design
is that a suitable material can be used for each cutting tool part.
It is thus in particular possible to use comparatively hard
materials having good cutting properties for the cutting tool part
on which the cutting edge is disposed. Less hard but more elastic
materials can be used for the cutting tool part comprising the
cutting tool shank.
[0008] In rotary cutting tools of the abovementioned type, it is
important that the two cutting tool parts forming the rotary
cutting tool are held together reliably. It is in particular
necessary to prevent the cutting tool parts from separating from
one another during operation of the rotary cutting tool under the
influence of elastic or plastic deformations that can occur during
an associated cutting process.
[0009] At the same time, however, it should also be possible to
separate the two cutting tool parts from one another quickly and
easily. The assembly of the cutting tool parts to form the rotary
cutting tool should likewise be quick and easy to carry out.
[0010] There is obviously some conflict of objectives between ease
of assembly and disassembly and firmly holding the parts
together.
SUMMARY
[0011] The object of the invention is therefore to further improve
known rotary cutting tools. The intent is in particular to specify
a rotary cutting tool, the cutting tool parts of which can be held
together particularly reliably and firmly. At the same time, the
cutting tool parts should be able to be easily separated from one
another and easily connected to one another.
[0012] The object is achieved by a rotary cutting tool of the
abovementioned type, in which the coupling mechanism comprises a
coupling cam that is mounted on one of the two cutting tool parts
such that it can rotate about an axis of rotation and, in a
coupling position, abuts an engagement surface on the other cutting
tool part, so that the first cutting tool part and the second
cutting tool part are coupled in the direction of the axis of
rotation. The first cutting tool part and the second cutting tool
part are thus secured to one another, in particular along a
pull-out direction. In the present case, a cam is understood to be
a rotatably mounted component that is also provided with a certain
eccentricity. When the coupling cam is in the coupling position and
abuts the engagement surface, the first cutting tool part and the
second cutting tool part are reliably coupled to one another via a
form-fitting connection and/or a frictional connection. By means of
the coupling cam, it is in particular possible to place the first
cutting tool part and the second cutting tool part against one
another with a certain amount of pretension along the axis of
rotation. This results in a particularly reliable coupling of the
two cutting tool parts. Such a coupling can be established quickly
and easily by rotating the coupling cam. Such a coupling can also
be released again quickly and easily by rotating the coupling cam
in an opposite direction. In other words, the cutting tool parts
forming such a rotary cutting tool can be coupled and uncoupled
quickly and easily.
[0013] To ensure that the two cutting tool parts are precisely
positioned relative to one another along the axis of rotation in
the coupled state, at least one axially aligned abutment surface
can be provided on one of the cutting tool parts which, in the
coupled state, abuts an axially aligned counter-abutment surface of
the other cutting tool part. The axially aligned abutment surface
and the axially aligned counter-abutment surface are in particular
separate from the coupling mechanism.
[0014] A centering surface can also be provided on one of the
cutting tool parts, which, in the coupled state, abuts a centering
counter surface of the other cutting tool part. The two cutting
tool parts can thus be reliably centered with respect to the axis
of rotation. The centering mechanism is also in particular
independent of the coupling mechanism.
[0015] When the rotary cutting tool is in operation, the cutting
tool part comprising the cutting tool shank is typically coupled to
a machine and driven in rotation. In order to be able to transmit a
torque from this cutting tool part to the cutting tool part on
which the cutting edge is disposed, a driver geometry can be
provided on one of the cutting tool parts, which interacts with an
associated counter geometry on the other cutting tool part. The
driver geometry and the associated counter geometry are likewise in
particular separate from the coupling mechanism.
[0016] According to one embodiment, in the coupling position of the
coupling cam, the first cutting tool part and the second cutting
tool part are coupled in a form-locking manner in the direction of
the axis of rotation. This results in a particularly reliable
coupling of the two cutting tool parts.
[0017] The axis of rotation of the coupling cam can extend
transverse, in particular perpendicular, to the axis of rotation of
the rotary cutting tool. The axis of rotation therefore extends
radially or diametrically with respect to the axis of rotation of
the rotary cutting tool. An influence of a rotation of the rotary
cutting tool about its axis of rotation on the coupling mechanism
is thus kept to a minimum or eliminated. In other words, influences
from the operation of the rotary cutting tool on the coupling
mechanism are low or non-existent. This too results in a more
reliable fastening of the two cutting tool parts to one
another.
[0018] According to one variant, the coupling cam is substantially
elliptical or parabolic in a cross-section oriented substantially
perpendicular to the axis of rotation. In this context, a parabolic
cross-section is to be understood to be a cross-section, the edge
of which is at least partly parabolic. A parabolic cross-section
can be composed of two parabolas, for example, in such a way that
the vertices of the parabolas face away from one another.
Therefore, as already mentioned, the coupling cam is eccentric in
cross-section with respect to the axis of rotation. The two cutting
tool parts can thus easily be connected to one another by rotating
the coupling cam about the axis of rotation. The cutting tool parts
can be separated from one another by rotating the coupling cam in
an opposite direction about the axis of rotation. Also, by means of
the elliptical or parabolic coupling cam, a pretension under which
the two cutting tool parts are placed against one another can be
adjusted substantially continuously and sensitively by rotating the
coupling cam.
[0019] The coupling cam is advantageously disposed in an end
portion of the first cutting tool part or the second cutting tool
part facing the respective other cutting tool part. The coupling
cam is therefore always positioned in the region of a connection
point between the two cutting tool parts. Forces required to couple
the cutting tool parts are consequently introduced comparatively
directly into the coupling mechanism. This results in a reliable
coupling. This also results in a simple structure of the rotary
cutting tool. Moreover, a region of the rotary cutting tool in
which the connection point is disposed is typically easily
accessible. This is true in particular when the rotary cutting tool
is clamped into an associated machine. This facilitates the
coupling and uncoupling of the cutting tool parts.
[0020] The coupling cam can be seated on a camshaft that is mounted
within the first cutting tool part or the second cutting tool part
such that it can rotate about the axis of rotation. A tool
engagement contour is in particular provided on at least one end of
the camshaft. The camshaft and with it the coupling cam can thus be
rotated by means of a tool that engages with the tool engagement
contour. As already mentioned, via such a rotation, a coupling or
uncoupling of the cutting tool parts can be effected in a simple
manner. In other words, the camshaft and associated coupling cam
can assume a coupling position in which the two cutting tool parts
are connected to one another, or an assembly position in which the
two cutting tool parts can be moved relative to one another. It
goes without saying that the tool engagement contour has to be
accessible from the outside of the cutting tool so that it can
interact with a tool. The tool engagement contour is in particular
accessible in a radial direction of the rotary cutting tool.
[0021] The coupling cam can be produced in one piece with the
camshaft or integrally connected to the camshaft. Both cases result
in a reliable holding together of the coupling cam and the
camshaft, which also results in a reliable coupling of the two
cutting tool parts. Such components can furthermore be produced
simply and inexpensively.
[0022] End-side bearing portions can be provided on the camshaft
for rotatably mounting the camshaft in the associated cutting tool
part. The end-side bearing portions are in particular rotationally
symmetric with respect to the axis of rotation. Moreover, in
particular in the case that the coupling cam and camshaft are
produced in one piece, a diameter of the bearing portions can be
selected such that its size is at least equal to the largest
diameter of the coupling cam. This ensures that the composite
consisting of the coupling cam and the camshaft can easily be
mounted on the associated cutting tool part. This composite is
advantageously inserted in radial direction into an associated
receiving space of the associated cutting tool part.
[0023] In one variant, the engagement surface forms an undercut
which acts in the direction of the axis of rotation of the rotary
cutting tool and in a separating direction of the cutting tool
parts. The separating direction refers to a direction oriented
along the axis of rotation in which the two cutting tool parts are
moved away from one another. The undercut allows the cutting tool
parts to be fastened to one another in a reliable manner.
[0024] According to one embodiment, it is provided that the
engagement surface comprises a cylinder jacket surface portion, in
particular a circular cylinder jacket surface portion or a jacket
surface portion of a cylinder having an elliptical bottom surface.
On the one hand, such an engagement surface can easily be produced
using standard production methods and machines. On the other hand,
in cooperation with the coupling cam which is in particular
elliptical in cross-section, such an engagement surface is a way of
precisely and reliably setting a pretensioning force or holding
force by means of which the two cutting tool parts are held
together by varying the degree of rotation of the coupling cam
relative to the engagement surface.
[0025] In one variant, a central axis associated with the cylinder
jacket portion extends transverse, preferably perpendicular, to the
axis of rotation of the rotary cutting tool. The central axis in
particular extends substantially parallel to the axis of rotation
of the coupling cam. This results in a compact structure of the
rotary cutting tool. It also ensures that the coupling cam abuts
the engagement surface with a line contact or a surface contact.
This leads to a reliable coupling of the cutting tool parts.
[0026] The engagement surface can be configured as a section of a
coupling groove, wherein the coupling groove is provided on the
first cutting tool part or on the second cutting tool part and an
opening of the coupling groove faces in the direction of the
respective other cutting tool part. The opening direction of the
coupling groove thus corresponds substantially to the axis of
rotation. This allows the cutting tool parts to be coupled to one
another and uncoupled from one another quickly and easily. Such a
structure furthermore saves space.
[0027] If the engagement surface forms an undercut, said undercut
acts in a depth direction of the coupling groove.
[0028] The engagement surface is in particular disposed in the
region of a groove base of the coupling groove. The engagement
surface can then at least form portions of the groove base. The
remaining portions of the coupling groove, in particular the
portions facing toward the opening, can therefore be used to align
the two cutting tool parts with one another before the coupling cam
is positioned in the region of the groove base, i.e. in the region
of the engagement surface. The coupling of the cutting tool parts
is thus facilitated.
[0029] The coupling cam and the coupling groove can be matched to
one another such that, in an assembly position, the coupling cam
can be slid along the axis of rotation of the rotary cutting tool
inside the coupling groove. In this context, the largest diameter
of the coupling cam is in particular oriented in a depth direction
of the coupling groove. The coupling cam can thus easily be
inserted into or moved out of the coupling groove. When the
coupling cam reaches the region of the groove base, it can be
rotated such that its maximum diameter is no longer oriented in the
depth direction of the coupling groove. This can result in a
form-fitting connection and/or a force-fitting connection, so that
the two cutting tool parts are reliably coupled to one another.
[0030] The object is further achieved by a cutting tool part, in
particular a cutting tool base, for a rotary cutting tool according
to the invention. The cutting tool part comprises a coupling
interface for coupling the cutting tool part to another cutting
tool part, wherein the coupling interface comprises a rotatably
mounted coupling cam. For such a cutting tool part, the effects and
advantages already mentioned with respect to the rotary cutting
tool in connection with a coupling cam result. Such a cutting tool
part can thus easily be coupled to another cutting tool part,
whereby the coupling is particularly reliable.
[0031] The object is also achieved by a cutting tool part, in
particular a cutting tip, for a rotary cutting tool according to
the invention. The cutting tool part comprises a coupling interface
for coupling the cutting tool part to another cutting tool part,
wherein the coupling interface comprises an engagement surface for
a coupling cam. In this context, too, the effects and advantages
for such a cutting tool part result as already discussed in
connection with the rotary cutting tool and an engagement surface
for the coupling cam. Such a cutting tool part can thus likewise
easily be coupled to another cutting tool part, whereby the
coupling is particularly reliable.
DETAILED DESCRIPTION
[0032] The invention is explained below with the aid of a design
example, which is shown in the accompanying drawings. The figures
show:
[0033] FIG. 1 in a schematic side view, a rotary cutting tool
according to the invention composed of two cutting tool parts
according to the invention,
[0034] FIG. 2 a detail II of the rotary cutting tool of FIG. 1 in a
perspective view,
[0035] FIG. 3 a diametric section through the portion of the rotary
cutting tool shown in FIG. 2, wherein a coupling cam is in an
assembly position,
[0036] FIG. 4 a sectional view corresponding to FIG. 3, wherein the
coupling cam is in a coupling position,
[0037] FIG. 5 a portion of one of the cutting tool parts according
to the invention of the rotary cutting tool of FIG. 1 comprising a
coupling interface,
[0038] FIG. 6 the other cutting tool part according to the
invention of the rotary cutting tool of FIG. 1, and
[0039] FIG. 7 a composite consisting of a coupling cam and a
camshaft of the rotary cutting tool of FIG. 1 in an isolated
illustration.
[0040] FIG. 1 shows a rotary cutting tool 10 which, in the
embodiment shown, is a drill.
[0041] The rotary cutting tool 10 comprises a first cutting tool
part 12 on which a cutting edge 14 is disposed. The first cutting
tool part 12 can therefore also be referred to as the cutting
tip.
[0042] The rotary cutting tool 10 also comprises a second cutting
tool part 16 which comprises a cutting tool shank 18. In simplified
form, the second cutting tool part 16 can therefore be referred to
as a cutting tool base or cutting tool shank.
[0043] The first cutting tool part 12 and the second cutting tool
part 16 are disposed adjacent one another along an axis of rotation
20 of the rotary cutting tool 10 and releasably connected to one
another via a coupling mechanism 22.
[0044] The coupling mechanism 22 is discussed in more detail below
with reference to FIGS. 2 to 7.
[0045] In this regard, the second cutting tool part 16 comprises a
coupling interface 24 for coupling with the first cutting tool part
12 (see in particular the isolated illustration in FIG. 5).
[0046] The coupling interface 24 comprises an axially oriented
abutment surface 26 against which the first cutting tool part 12
can be placed along the axis of rotation 20. The coupling interface
24 also comprises two centering surfaces 28a, 28b by means of which
the first cutting tool part 12 can be centered on the second
cutting tool part 16.
[0047] The centering surfaces 28a, 28b are configured as radial
inner surfaces of two driver fingers 30a, 30b.
[0048] The driver fingers 30a, 30b also serve to introduce a
torque, starting from the second cutting tool part 16, into the
first cutting tool part 12, which of course carries the cutting
edge 14.
[0049] For coupling the two cutting tool parts 12, 16, the coupling
interface 24 also comprises a rotatably mounted coupling cam 32
(see in particular FIGS. 2 and 7).
[0050] In the present case, the coupling cam 32 is produced in one
piece with a camshaft 34.
[0051] The composite consisting of the camshaft 34 and the coupling
cam 32 is mounted in the second cutting tool part 16 such that it
can rotate about an axis of rotation 36.
[0052] A tool engagement contour 37 is also provided at one end of
the camshaft 34, so that the camshaft 34 can be rotated together
with the coupling cam 32 by means of a tool.
[0053] As is evident in particular from the illustration of FIG. 2,
the coupling cam 32 is mounted together with the camshaft 34 in an
end portion of the second cutting tool part 16 which faces the
first cutting tool part 12.
[0054] The coupling cam 32 is furthermore elliptical in a
cross-section oriented substantially perpendicular to the axis of
rotation 36 (see FIGS. 3 and 4).
[0055] The axis of rotation 36 of the coupling cam 32 extends
substantially perpendicular to the axis of rotation 20 of the
rotary cutting tool 10 (see FIGS. 3 to 5).
[0056] The coupling mechanism 22 also comprises an engagement
surface 38, which is disposed in the region of a groove base 40 of
a coupling groove 42.
[0057] The coupling groove 42 is configured on the first cutting
tool part 12 and extends substantially diametrically with respect
to the axis of rotation 20 (see FIGS. 3, 4 and 6).
[0058] The coupling groove 42 is furthermore open in the direction
of the second cutting tool part 16.
[0059] The engagement surface 38 is configured as a circular
cylinder jacket surface portion, the associated central axis 43 of
which, on the one hand, extends perpendicular to the axis of
rotation 20 of the rotary cutting tool 10 and, on the other hand,
is aligned substantially parallel to the axis of rotation 36 of the
coupling cam 32 (see FIGS. 3 and 4).
[0060] The engagement surface 38 also forms an undercut 44 which
acts in the direction of the axis of rotation 20 of the rotary
cutting tool 10.
[0061] The coupling groove 42 with the engagement surface 38 thus
forms a coupling interface 46 of the first cutting tool part 12 for
coupling with the second cutting tool part 16.
[0062] The coupling cam 32 can assume two specific positions when
it interacts with the engagement surface 38.
[0063] In an assembly position, which can in particular be seen in
FIG. 3, a largest diameter D.sub.max of the coupling cam 32 is
oriented along the axis of rotation 20.
[0064] Consequently, the largest diameter D.sub.max of the coupling
cam 32 is also oriented along a depth direction of the coupling
groove 42.
[0065] The coupling cam 32 and the coupling groove are matched to
one another such that, in this assembly position, the coupling cam
32 can be slid along the depth direction inside the coupling groove
42.
[0066] In other words, a groove width d is at least slightly larger
than a smallest diameter D.sub.min of the coupling cam which is
then oriented transverse to the axis of rotation 20 and transverse
to the depth direction of the coupling groove 42.
[0067] Now, when the first cutting tool part 12 is aligned along
the axis of rotation 20 relative to the second cutting tool part 16
such that it abuts the axial abutment surface 26, the coupling cam
32 is located in the region of the groove base 40 of the coupling
groove 42. It can now be rotated about the axis of rotation 36 so
that it assumes a coupling position in which it abuts the
engagement surface 38 (see FIG. 4).
[0068] Since the largest diameter D.sub.max of the coupling cam 32
is now no longer oriented along the axis of rotation 20 but
transversely to it, said coupling cam engages behind the undercut
44.
[0069] As a result, the two cutting tool parts 12, 16 are coupled
to one another in a form-locking manner.
[0070] This form-locking coupling exists in particular along the
axis of rotation 20 and in a direction in which the two cutting
tool parts 12, 16 are separated from one another, i.e. removed from
one another.
* * * * *